A Superconductor-Insulator-Superconductor (SIS) mixer using parallel array of N junctions have been studied. It has been shown by theoretical analysis that the performance of this type of device is excellent and that nearly quantum-limited performance of the mixer can be obtained. It has been demonstrated that the double sideband (DSB) noise temperature of a receiver employing parallel array of twin junctions, which is the most simplest case in the parallel array of N junctions, was approximately 3 to 5 times as large as the quantum limited photon noise up to the gap frequency of Nb (approximately 700 GHz). It has been also shown that the bandwidth performance of parallel junction arrays can be improved significantly with a large number of SIS junctions even if SIS junctions with a relatively low current density or a large (omega) R_NC_J product are adopted in the arrays.

Date Published: 3 July 2000
PDF: 9 pages
Proc. SPIE 4015, Radio Telescopes, (3 July 2000); doi: 10.1117/12.390438

Published in SPIE Proceedings Vol. 4015:
Radio Telescopes
Harvey R. Butcher, Editor(s)